This invention relates to an electro-optical display device having both a segment display and a dot matrix display employing electro-optical material, e.g., liquid crystal, PLZT or single crystal material which exhibits the electro-optical effect such as gadolinium molybdate.
Recently, a micro calculator, a watch or the like having a digital display have become more popular due to the development of the electro-optical material, e.g., liquid crystal. On the display device of the micro calculator or watch, an electrode structure of the 7-segment type, which forms the numeral letter 8, is generally used for displaying numerals and letters. Further a dot matrix display device using liquid crystal has been developed for the display part of the terminal equipment of a computer. An advantage according to the segment display is that it is able to display numeral letters or simple letters. The dot matrix display is disadvantageous in that it needs many electrodes for display. The dot matrix display, however, has an advantage in that it can provide almost all displays, e.g., numeral letters or letters and give fine numeral letter or letter displays. Furthermore, by providing a memory circuit and suitably selecting a decoder, it is possible to easily change the letter for display.
On the liquid crystal display for a watch, the segment display of the 7-segment type which forms the figure 8 is used for displaying the information of time. In a timepiece, the display of hour, minute, second, date, year or the like by numeral letters using the segment display of the 7-segment type can be readily obtained. However, displaying letters, e.g., 7 days, by the segment display has disadvantages which makes the letter large in part and makes the letter difficult to read. Using the display, it is almost impossible to change English letters, Japanese letters or the like to another letter.
It is an object of the invention to overcome the foregoing disadvantages. It is another object of the invention to provide an electro-optical display device which has fine display letters and a means to change easily the letter, e.g., Japanese letters or English letters. It is another object of the invention to provide an electro-optical display device which has a simple structure and has merits of both the dot matrix display and the segment display.